Last week, Colin Mathura-Jeffree sent me a kind email about something I'd written and said we should catch up. You could have knocked me down with a feather -or at least a feather boa. You can imagine him in a feather boa. He's about the only person, never mind bloke, in the country who could wear one and make it look like fashion. But when we did catch up, he was wearing a checked suit with a checked shirt, and gumboots. The suit was a bit tight.

"It's supposed to be tight." He had got fatter (haven't we all) since I saw him last. He likes being fatter. He didn't mind me saying his suit was tight. He's very good-natured. You have to be to be a good model, he says.

I last met him 15 years ago when he was but a callow youth - he is now 40. He had recently returned from Mumbai and was about to head back there, where he was, he told me, a supermodel. He told me all sorts of wondrous stories of princesses and penthouses and being waited on hand and foot.

Of course nobody had ever heard of him then and I thought: "Who does he think he is?"

He had all sorts of schemes which sounded like pie in the sky to me. I remember that he wasn't altogether pleased with what I wrote and he phoned and carried on, but he can't remember this at all - and why would he? Had he wanted to be famous then? He laughed like anything when I asked. "No. Famous has really, really, never been my agenda. I could say something ... I'd better not." Oh, go on. "The thing is ... I thought I was famous! Ha, ha, ha!"

What does it matter what I thought of him then? I've watched his mad career as a telly star ever since with wide-eyed, jaw-dropped fascination. Who could have predicted he would become this fabulous, famous creature leading a fabulous, famous life? He could have; he did. I just didn't believe him. I certainly don't remember him being funny. But he is.

He was sweet too. He invited me to his 40th birthday party in May. Did he really? Something went wrong with the invitations and I didn't get mine. He says his family didn't get theirs either and he had to put their names on the door. But why would he invite me? "Because it wasn't just about having people that I knew, I wanted people that I'm interested in. And I thought you might enjoy yourself ."

I might have too. He wanted a proper party, for 500, where everything was put on, lashings of it, all night long. "I wanted to have a party to just really show people how to have a party. There's absolutely nothing worse than a party where halfway through the night someone goes: 'Now it's a cash bar'." Also, "I don't imagine I'll ever get married."

It must have cost as much as a wedding. "It doesn't matter because at the end of the day, we're not born with money on our bodies." What on earth does he mean? "I'm not going to die and take it with me." So, did he pay for it? "No! Ha, ha. Partially!" Of course, he didn't pay for all of it. Honestly, there's no point in being Colin Mathura-Jeffree if you have to pay for things. I was being very boring. And I had very nicely pedicured toes in Cajun Shrimp, gratis, because I was tagging along with the famous person.

Lunch had been put on for us in the Presidential suite of the Pullman. When they took the wine bottles away, he said, "Call them up", and I did and the wine bottles came back. We were waited on hand and foot. He pretended he kept the waitress under the table. He was charming and polite to her. He's naughty but he remembers his manners.

Is this what his life is like? "Now? It's pretty much always been like this! I enjoy this side of life. I like this playfulness. This is fun. And we can get away with it!" He says if he'd had more notice, he'd have arranged for us to be flown to Sydney. He is about the only person I can think of who could have got away with such a grand gesture and not have come across as a total plonker.

He was once asked, when the America's Next Top Model crew were on Mt Eden, just after dawn, in driving rain, if they could get him anything. He said: "A cheeseboard." They thought he was being a diva; he was being a clown. An enormous cheeseboard arrived. Of course he didn't eat it.

I have long thought I'd like to interview him again but thought there was little point asking. He said now that no, no, no, he didn't want to do an interview. He wanted me to write a book. I said I'd write his and he said, no, he'd write his own book - and it would be a colouring-in book. I believe the first part of this. The point of our meeting would be so he could give me a motivational talk which would inspire me to write a book.

So he's still talking a load of nonsense because, I told him, I was far too lazy but not too lazy for a long interview over a long lunch. Then he phoned back to say he'd booked us into the spa at the hotel. He seems to have some sort of arrangement with them whereby he turns up and gets gold facials or wrapped in foil and cooked like a giant chook, and then tweets about it. I would rather go to a dentist than to a spa (how very clever of him to have guessed) so I said, oh, no we weren't. He booked us in to the spa. It was his revenge.

Which is why on Wednesday morning, I was sitting in a room, in a spa when that fabulous creature from the telly rushed in brandishing a very small paper thong. He was wearing a dressing gown which gaped a bit, in places. He couldn't work out which way round the thong went. Also, it was too small, either way. The mind would have boggled, if one had let it, which, being the possessor of a prudish mind, one didn't.

Really! We'd just met. He is not, it is fair to say, decorous. He said he was demure and shy, but that was just so that he could show how fetching he looks when he flutters his eyelashes. He also said that when people pay him lots of money to give speeches and MC and so on, they are hiring a character. I asked how much he charged and he said it depended. $5000? He gave a Cheshire cat grin.

He is a strangely relaxing person to be around, for all the fluffing and pampering. "I'm secure and I try to make other people feel secure," he said. And: "I'm not harmful. I'm harmless." He gives the appearance of being confiding, although how much do we really know about him?

It turns out we live near each other and he spent the taxi ride home telling me I am to invite him over and provide margaritas and tapas. He got out of the cab around the corner from his house. I could see where he lived, once he'd seen where I did. He likes dinosaurs, and would have been a palaeontologist if he hadn't become a model; reading; talking; cats and privacy.

Everyone thinks they know he's gay: He says it's nobody's business. "I don't invite people into my bedroom." What's his bedroom like? "Delicious!" He has never been in love. "I think I've danced around the feelings of love, but I've never committed. My career was built on being alone a lot of the time. I looked at other models, suffering under love, you know, from partners: 'Why were you in a photo with that person?' So I decided to distance myself."

It seems very hard-headed. "I suppose so. But I'm not alone and I'm not lacking in love in my life."

People also think that he's a "vacuous airhead". As if he cares. "I read!" He has always been very career-minded and sensible. He's financially canny; he has a healthy retirement fund; he has saved his money. "I'm Indian!"

He's a happy narcissist but he says all men are. I think he means all beautiful men, although he doesn't think he's beautiful. Of course he is. "That's so sweet of you. I don't particularly think I'm beautiful. I'm photogenic and I think I'm exotic and I know how to dress and I know how to be."

Honestly, he does talk some rot. How to be? "Well, I know how to be present in a situation. Even though you might be thinking: 'Someone in a penthouse in an amazing hotel is not present'." That was exactly what I was thinking, or sort of what I might have been thinking if I hadn't been thinking what rot he was talking.

Oh who cares? It's entertaining rot and he's far too much of a down-to-earth New Zealander not to know it. I suppose he's picked it up from hanging around with Americans. He talks about being on a "journey", but almost everybody does now. And he did take it well and cackled when I said, rudely: "Are you on a bus?"

He said: "A gift is never about money; it's always about thought." After which was a long pause, for, I assumed, portentous effect. "That's as deep as I get. Ha, ha."

He is remarkably easy-going; all those years in the modelling industry will do that to you. He told a very funny story about getting changed for a Versace shoot and throwing pants back over the curtain of the changing room because they didn't fit. All he could hear coming from the other side was: "Colin! You've got fat!" Behind the curtain he laughed so hard he had to stuff his fist in his mouth.

Modelling is ridiculous. People say: "Colin! Colin! Do a pose for us!" He got up and did a pose for us. He stood, poutily, forehead against the wall. "It's a far tougher job than people assume, and also ridiculous. Who stands against a wall? That's what I love about it: How ridiculous it is. It's just so silly, it's fun."

We had a silly, fun gossip about celebrities. O drinks like a fish. He said, "I hear N is a hermaphrodite!" I told him about the celebrity who was three hours late for an interview. He was early. He said: "I tried to be late! I should be more fabulous."

Imagine it! I'd like to interview him again in another 15 years. Surely he can only get more fabulous with age.